In the design of automobiles, the transfer of a new design from a blueprint to a three-dimensional clay model is an important step. Clay models of new automobile designs have been used for many years for the evaluation of design concepts. It enables an automobile designer to view his design in real dimension.
Modeling clays that can be shaped by hand at room temperature have been used in making automobile clay models. The clay material is first heated and then spread and sculptured to the shape of an automobile.
It is desirable at some point in the design process for the designer to evaluate an automobile clay model with a high quality paint coat layer finish so that the designer can properly evaluate the design as it would appear in a production process. I use the term paint coat layer to broadly define a layer of at least one color coat alone, layers of at least one primer coat and at least one color coat, or layers of at least one primer coat, at least one color coat and at least one clear coat. Prior to the onset of the present invention, this would require that the clay body be sent to a molding department where plaster molds would be cast from the clay body and a fiberglass skin then built-up inside the plaster molds.
The fiberglass skin would then be surface finished and sent to a paint department where the fiberglass skin would be painted to the quality level of a production vehicle. The entire process would take two to three weeks and consuming approximately 360 man-hours. Frequently, the clay body is damaged in the plaster casting process and requires extensive and costly repair work.
The present invention provides a method which permits the painting of a clay body directly with a high gloss finish in two to three days or approximately 40 man-hours. Alternatively, a strippable coating may first be applied onto the clay body (as shown in our preferred embodiment), if the designer decides to make changes in the clay body, the paint coat layer can be peeled off of the clay body and the clay modeling process can continue.
In either of these two processes, problems are frequently encountered in maintaining a durable paint coat finish on the clay model. Since the clay material used in shaping clay models normally contains a large amount of oily substances, these oily substances migrate from the body of the clay to the surface of the clay model causing blisters and subsequent separations of the paint coat film from the strippable layer or from the clay surface. The use of the strippable coating layer on the clay surface does not stop the permeation of the oily substances from the clay body to the paint coat layer. It has been observed that the paint coat layer applied directly on the clay body or on the strippable coating layer would not maintain its desirable finish more than approximately one month after it is applied.
It is, therefore, an object of the present invention to provide a method of painting clay bodies by providing a barrier film layer between the paint coat layer and the clay body such that the oily substance contained in the clay body is blocked from permeating through the barrier film to adversely affect the paint coat finish.
It is another object of the present invention to provide a method of painting a clay body on a strippable coating layer and maintaining a durable, decorative surface finish by providing a barrier film layer between the paint coat layer and the strippable coating-clay body such that the oily substance contained in the clay body is blocked from permeating through the barrier film to adversely affect the paint coat finish.